Sudden infant death syndrome (SIDS) has been the leading cause of death for infants aged one month to one year in the United States for the past two decades, with more than 5,000 SIDS deaths occurring annually prior to 1992. Since 1992 the Reduce the Risks public health campaign, Together with the US Public Health Service Back to Sleep campaign beginning in 1994, has been associated with at least a 40% reduction in SIDS mortality rates in the US. Previously, we published results on the progress achieved since 1992 in changing infant sleep position in the US. This past year we have continued to analyze the annual surveys conducted for the National Infant Sleep Position (NISP) study. A paper has been submitted for publication that describes the factors that have most influenced parents and other caregivers to place their infants to sleep in non-prone positions (side or back). The reasons given by the caregiver were the major determinants of infant placement. Back (supine) placement is strongly influenced by the content and source of the recommendation. Caregivers who were afraid of vomiting, choking, and spitting-up were less likely to place their babies in a supine position. Since the national campaign to reduce prone (stomach) placement seems to have reached a plateau, this study aims at showing areas where additional emphasis could further reduce SIDS risk. Also this year we have analyzed national, linked vital statistics data for the period 1990-1991 versus 1995-1996 to investigate whether SIDS risk factors in the US have changed from the era prior to the Back to Sleep public health campaign to the present. Besides changing infant sleep position from stomach to side or back, there remain many other important, potentially modifiable risk factors for SIDS. These national data indicate the importance of young maternal age and relatively high parity as continuing factors increasing SIDS risk, after adjustment for several other known risk factors. We have also examined trends in maternal smoking, which in the absence of prone sleeping position emerges as one of the main preventable risk factors for SIDS. In addition, we have participated in the Chicago SIDS/Infant Mortality Study and a paper is in press which showed that in this population laryngeal basement membrane thickening is not a marker for infants dying of SIDS. Also, results have been presented from a PCR study of infections in SIDS cases and control infants from a collaborative effort with researchers at Allegheny University and the University of Maryland. Also this year a population-based, long-term follow-up study of very low birth weight (VLBW) infants and control children in Missouri began recruiting subjects. Previously we have published outcomes for this high risk population based on the Denver II Developmental Screening Exam. Also, we have presented information comparing the outcomes for those infants sent home from the newborn nursery on apnea monitors with birth weight matched control infants. The infants with home apnea monitors were relatively delayed in terms of gross and fine motor development and also on speech/language measures. The follow-up study will provide the opportunity to investigate whether the high risk children outgrow these delays by nine years of age, or instead, continue to lag behind in audiometric and speech/language assessments. - SIDS, infant sleep position, prone, cigarette smoking, maternal age, apnea, laryngeal basement membrane, Developmental Screening Exam - Human Subjects & Human Subjects: Interview, Questionaires, or Surveys Only